JP2685337B2 - Method for producing poly (arylene sulfide) composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of making a poly (arylene sulfide) composition. In another aspect, the invention relates to a method of making a poly (arylene sulfide) composition useful in the production of fibers and monofilaments.

A method for producing a poly (arylene sulfide) polymer, which is used for various purposes in industry and commerce, is known. The use of poly (arylene sulfide) polymers has proved desirable due to their high chemical, temperature and electrical resistance. Although U.S. Pat. No. 3,919,177 describes a commercially useful process for making poly (arylene sulfide) polymers, this process for producing poly (arylene sulfide) has been further developed to have improved properties and in some cases Manufactures polymers with special industrial uses.

For example, poly (arylene sulfide) polymers have been used in the production of fibers and monofilaments. Poly (arylene sulfide) polymers produced according to conventional methods often have problems when spinning the polymers into fibers or monofilaments. The problems encountered are fiber and filament breakage, poor color of the resulting fibers or monofilaments, adhesion of the polymer itself to the die surface and poor spinnability. These problems are caused by the presence of volatile components in the polymer, such as, for example, molecular weight poly (arylene sulfides) (ie oligomers), unreacted monomers, salt by-products and the like. Another problem is due to the lack of oxidative or melt stability required for long-term processing at elevated temperatures when used to make fibers or monofilaments.
Therefore, it would be desirable to have a method for making poly (arylene sulfide) polymers that can be spun into fibers or monofilaments without the above problems.

Therefore, it is an object of the present invention to provide a method for producing a poly (arylene sulfide) composition having a low content of impurities and volatile compounds.

To provide a method for producing a poly (arylene sulfide) composition having good oxidative stability and melt stability,
It is another object of the present invention.

Yet another object of the present invention is to provide a method of making poly (arylene sulfide) compositions useful in making fibers and monofilaments.

According to the invention, the following steps are carried out: (a) a sulfur source, a dihalogenation under suitable conditions to form a substantially liquid mixture of a poly (arylene sulfide) polymer, a polar organic compound and water. A step of contacting an aromatic compound, a polar organic compound, a base and a carboxylate of an alkali metal so that the molar ratio of the base to the sulfur source before dehydration does not exceed about 0.98: 1; (b) Gradually cooling Forming a slurry containing solid poly (arylene sulfide) particles and a liquid composed of a polar organic compound and water, and adding an effective amount of at least one kind of extractant; (c) poly (arylene sulfide) particles And a calcium ion-containing aqueous solution, and (d) recovering the poly (arylene sulfide) composition. And a method for producing the composition. The poly (arylene sulfide) composition produced according to the present invention has a low content of impurities and volatile components, and therefore the poly (arylene sulfide)
Useful for producing fibers and monofilaments.

The poly (arylene sulfide) composition of the present invention is a sulfur source under suitable conditions, one dihalogenated aromatic compound and any other halogenated aromatic compound, polar organic compound, base and alkali metal carboxylic acid. It is produced by contacting with salt.

Dihalogenated aromatic compounds suitable for use in the present invention have the formula: [In the formula, X is halogen, R is hydrogen, and has 6 to 24 carbon atoms.
Selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl and arylalkyl radicals]. Examples of suitable dihalogenated aromatic compounds include p-dichlorobenzene, p-dibromobenzene, p
-Diiodobenzene, 1-chloro-4-bromobenzene, 1
-Chloro-4-iodobenzene, 1-bromo-4-iodobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-
Xylene, 1-ethyl-4-isopropyl-2,5-dibromobenzene, 1,2,4,5-tetramethyl-3,6-dichlorobenzene, 1-butyl-4-cyclohexyl-2,5-dichlorobenzene, 1-hexyl-3-dodecyl-2,5-dichlorobenzene, 1-octadecyl-2,5-diiodobenzene,
1-phenyl-2-chloro-5-bromobenzene, 1-p
-Tolyl-2,5-dibromobenzene, 1-benzyl-2,5-
There are dichlorobenzene, 1-octyl-5- (3-methylcyclopentyl) -2,5-dichlorobenzene and the like and mixtures thereof. The preferred dihalogenated aromatic compound for use in the present invention is p-dichlorobenzene (DCB).

The poly (arylene sulfide) can optionally include up to about 10 mole percent di- or tri-halogenated aromatic comonomer which does not adversely affect fiber formation or properties.
Such comonomers include ethers, sulfones, ketones,
It may contain biphenyl, or naphthalene groups, and may contain meta-substituted dihaloaromatic compounds.

Suitable polar organic compounds for use in the present invention are one molecule of cyclic or acyclic organic amines having 1 to 10 carbon atoms. Suitable examples include formamide, acetamide, N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-ethylpropionamide, N, N-dimethylformamide, 2-pyrrolidone, N-methyl- 2-pyrrolidone, ε-caplacactam, N-methyl-ε-caplactam,
There are N, N'-ethylenedi-2-pyrrolidone, hexamethylphosphoramide, tetramethylurea, etc. and mixtures thereof. The preferred polar organic compound for use in the present invention is N-methyl-2-pyrrolidone (NMP).

Any suitable yellowing source can be used in the present invention.
Suitable sulfur sources include thiosulfates, substituted and unsubstituted thioureas, cyclic and acyclic thioamides, thiocarbamates, thiocarbonates, trithiocarbonates,
There are organic sulfur-containing compounds selected from the group consisting of mercaptans, mercaptides and sulfides, hydrogen sulfide, phosphorus pentasulfide, carbon disulfide, carbon oxysulfide, alkali metal sulfides and alkali metal hydrogen sulfides, and mixtures thereof. It is generally preferred to use an alkali metal hydrogen sulfide selected from the group consisting of sodium, potassium, lithium, rubidium and cesium as the source of sulfur for the present invention. The preferred alkali metal hydrogen sulfide is sodium hydrogen sulfide (NaSH). The alkali metal hydrogen sulfide is usually in the hydrated form and / or as an aqueous mixture,
It is preferably used in a liquid state at a use temperature. The water present with the alkali metal hydrogen sulfide can vary over a considerable range, and generally, the alkali metal hydrogen sulfide is about 20 to about 50% based on the total weight of the water associated with the alkali metal hydrogen sulfide in the solution or hydrate. It is present in an amount in the range of about 70% by weight, preferably about 25 to about 60% by weight.

Suitable bases for use in the present invention include lithium hydroxide,
There are alkali metal hydroxides including sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures thereof. If desired, hydroxides can be produced on-site by reaction of the corresponding oxides with water. The preferred base for use in the present invention is sodium hydroxide (NaOH). The alkali metal hydroxide can be used in anhydrous form, but is preferably used in hydrated form and / or as an aqueous mixture, especially in liquid form at the temperature of use. The water present with the alkali metal hydroxide can vary over a considerable range, but generally alkali metal hydroxide is up to about 70% by weight, based on the total weight of water associated with the alkali metal hydroxide in solution or hydrate. Preferably present in an amount of about 25 to about 60% by weight.

Suitable alkali metal carboxylates for use in the present invention are of the formula: RCO ₂ M, where R is alkyl, cycloalkyl, aryl as well as their alkylalkyl, cycloalkyl, cycloalkylalkyl, arylalkyl, arylcyclo groups. A hydrocarbyl radical having 1 to 20 carbon atoms selected from the group consisting of combinations such as alkyl, alkylarylalkyl and alkylcycloalkylalkyl, M being an alkali selected from the group consisting of lithium, sodium, potassium, rubidium and cesium. Is a metal). R
Is an alkyl radical having 1 to about 6 carbon atoms or a phenyl radical, and M is preferably lithium or sodium. If desired, the alkali metal carboxylate salt can be used as a hydrate or solution or dispersed in water. If desired, the alkali metal carboxylates can also be prepared in situ by reaction of the corresponding carboxylic acids with alkali metal hydroxides or carbonates.

Examples of alkali metal carboxylic acids that can be used in the method of the present invention include lithium acetate, sodium acetate, potassium acetate, lithium propionate, sodium propionate, 2-methyl-lithium propionate, rubidium butyrate, lithium valerate, Sodium valerate, cesium hexanoate, lithium heptanoate, lithium 2-methyloctanoate, potassium dodecanoate, rubidium 4-ethyltetradodecanoate, sodium octadecanoate, sodium heneicosane, lithium cyclohexanecarboxylate, cesium cyclododecanecarboxylate Sodium 3,3-methylcyclopentanecarboxylate, potassium cyclohexylacetate, potassium benzoate, lithium benzoate, sodium benzoate, potassium m-tolueneate, lithium phenylacetate, 4-phenylcyclohexyl Sodium San carboxylic acid, p
-Potassium tolyl acetate, lithium 4-ethylcyclohexyl acetate and the like and mixtures thereof. The preferred alkali metal carboxylate salt for use in the present invention is sodium acetate (NaOAc).

The ratio of reactants can vary considerably, but the ratio of grams dihalogenated aromatic compound / grams divalent sulfur atoms in the sulfur source is in the range of 0.9 to about 1.3, preferably 0.95 to 1.1. Gram moles of alkali metal carboxylate per gram mole of dihalogenated aromatic compound is 0.
It is within the range of 05 to about 4, preferably 0.1 to 2. The amount of polar organic compound used in the polymerization reaction mixture can vary considerably. Generally, the molar ratio of polar organic compound / alkali metal hydrogen sulfide is within the range of about 1: 1 to about 10: 1, preferably about 2: 1 to about.
It is in the range of 5: 1. The base / sulfur source molar ratio in the present invention should not exceed 0.98: 1 prior to dehydration,
It is preferably 6: 1.

In the preparation of poly (arylene sulfide) polymers by the method of the present invention, alkali metal hydroxide and alkali metal carboxylate are usually mixed with an aqueous mixture of alkali metal hydrogen sulfide and a polar organic compound. After adding the alkali metal hydroxide, substantially all of the water is removed by distillation to form a dehydrated composition derived from the alkali metal hydroxide, alkali metal hydrogen sulfide and polar organic compound. The dihalogenated aromatic compound and any other halogenated aromatic compound are then combined with this dehydrated mixture to form a polymerization reaction mixture.

The temperature at which the polymerization is carried out can vary over a wide range and is generally in the range 215 ° C to 375 ° C, preferably 225 ° C to 285 ° C. The reaction time is in the range of 10 minutes to about 3 days, preferably 1 hour to 8 hours. The pressure need only be sufficient to maintain the dihalogenated aromatic compound and the organic compound substantially in the liquid phase and retain the sulfur source therein.

At the end of the polymerization reaction, poly (arylene sulfide)
The reaction mixture consisting of polymer, polar organic compound and water should generally be in a substantially liquid state at the reaction temperature. According to the invention, the mixture is preferably about
The poly (arylene sulfide) polymer is recovered by gradual cooling to a temperature in the range of 150 ° C to 230 ° C and, if desired, optionally adding a separating agent to the mixture for particle size control. A cooled mixture or slurry containing solid poly (arylene sulfide) particles, polar organic compounds, non-polymeric materials and low molecular weight materials for removing at least a portion of the low molecular weight organic materials from the solid poly (arylene sulfide) polymer. Under conditions suitable for
Contacting with an effective amount of at least one extractant.

The use of a separating agent to separate molten poly (arylene sulfide) from polar organic compounds is described in US Pat. No. 4,415,729, which is hereby incorporated by reference. The preferred separating agent is water, the amount of which is NMP.
When is used as the polar organic compound, it is typically about 0.05 to about 2 moles of separating agent per mole of polar organic compound.
The extractant / separating agent ratio is typically in the range of about 1/1 to 10/1 when the separating agent is water and the extracting agent is also NMP. The addition of the separating agent and the gradual cooling can be carried out in any order or at the same time, or a part of the separating agent may be added, followed by a gradual cooling period, and then the extraction agent may be added again. it can. "Slow cooling" means that the reactor does not use external cooling means.
Generally, the cooling rate does not exceed about 1 ° C (1.8 ° F) / min.

Suitable extractants for use in the present invention are those compounds that are useful for extracting low molecular weight materials and reactants from a poly (arylene sulfide) polymerization reaction mixture.
Suitable examples are the polar organic compounds already mentioned as polymerization reactants, NMP being the presently preferred extractant. The extractant is added to the reactor slurry in any manner to remove at least a portion of the low molecular weight organic material present in the solid poly (arylene sulfide). For example, the extractant can be added to the cooled slurry, or the slurry can be transferred to another container containing the extractant. Alternatively, a portion of the extractant can be added to the slurry and the mixture transferred to another container containing the rest of the extractant.

The amount of extractant added to the polymerization mixture depends on the extractant used and the sequence of addition of extractant and cooling used. For example, the amount of extractant NMP used to extract poly (phenylene sulfide) is generally such that the number of NMP moles added / the number of NMP moles used as a polar organic solvent is about 0.5 / 1 to about 2/1, more preferably the extractant mole / Mole of polar organic compound Within the range of 0.75 to 1.5. If the extractant is too small, the removal of low molecular weight substances will be insufficient, and if the extractant is too large, the extraction will not be improved and the extractant recovery cost will be high.

The extraction temperature is generally in the range of about 100 ° C to about 200 ° C.
At temperatures below 100 ° C, the extraction process is slow and inefficient. The contact time varies depending on the temperature, but is generally within the range of several minutes to several hours. Very short contact times result in poor extraction, and very long contact times do not significantly increase the extracted material. Sufficient stirring of the mixture during extraction improves the contact between the solid poly (arylene sulfide) particles and the extractant.

After the extraction step, the mixture can be separated into solid poly (arylene sulfide) particles and liquid by conventional methods such as filtration and centrifugation. The solid poly (arylene sulfide) can be washed with water to remove the inorganic byproducts of the polymerization.

The poly (arylene sulfide) particles are isolated, washed and then contacted with an aqueous solution containing calcium ions. Calcium ions are introduced as water-soluble metal salts, oxides and hydroxides. Examples include calcium chloride, calcium bromide, calcium acetate, calcium benzoate, calcium hydroxide, calcium oxide and mixtures thereof. The presently preferred source of calcium ions is calcium acetate. Treatment of the polymer with the calcium ion solution can be carried out at ambient temperature or at an elevated temperature such that it is below the melting point of the polymer for a sufficient period of time. The operation of this step is readily carried out with the wet polymer at temperatures in the range of 50 ° to 85 ° C (122 ° to 185 ° F). The operation can also be carried out from ambient temperature to a temperature no higher than about 14 ° C (25 ° F) below the melting point of the polymer, preferably from about 27 ° C (80 ° F) to about 271 ° C (520 ° F). .

Treatment time or contact time can vary greatly depending on the temperature and properties of the poly (arylene sulfide) polymer. This time is generally in the range of 5 minutes to 24 hours, preferably 30 minutes to 10 hours. In general, the contact time can be said to decrease with increasing temperature.
The pressure should be sufficient to maintain the liquid state and ranges from 0 to about 1500 psi. An iterative process can be used if desired. Alternatively, the process can be carried out in several phases.

The polymer / water slurry is 5-60 wt% polymer, more preferably for convenient handling and separation elements.
It may contain from 10 to 50% by weight of polymer.

Following treatment with calcium ions, the poly (arylene sulfide) composition can be recovered using any suitable technique known to those of skill in the art, such as washing with water, centrifugation, filtration, and the like. The amount of calcium present in the calcium treated and washed poly (arylene sulfide) is typically about 100 to about 1000 ppm, preferably 200 to 800 ppm. If desired, the polymer can be subsequently dried for later use.

In one embodiment of the invention, the poly (arylene sulfide) composition produced as described above is processed to form fibers and monofilaments. The poly (arylene sulfide) composition is first pelletized using conventional equipment, such as a single screw or twin screw extruder, preferably equipped with a vacuum vent to remove volatiles and moisture. It is also advantageous to use an excess device to remove impurities. The pellets can then be dried in a device such as a rotary drum dryer for later use. The temperature and time used in the drying step are not critical, but excessive time and temperature should be avoided to minimize pellet oxidation.

The poly (arylene sulfide) composition produced according to the present invention can be spun into staple, continuous monofilament, or monofilament fibers by most conventional melt spinnig equipment. Generally, a metering pump is used and a 325 mesh screen or finer screen is used for the spinpack. Temperatures in the range of about 280 ° to 340 ° C are used, with temperatures in the range of 290 ° to 320 ° C being particularly preferred.
Poly (arylene sulfide) fibers can be drawn at temperatures in the range of 90 ° to 110 ° C. using conventional equipment with drawing zones designed to heat the fibers to a suitable temperature. After drawing the fibers, the fibers can be at least partially crystallized using hot rolls or heating zones within the temperature range of 100 ° to 200 ° C. This fiber can then be converted to a table by any method known to those skilled in the art.

The poly (arylene sulfide) composition produced by the method of the present invention exhibits features that are desirable for good fiber resins. For example, a good quality linear poly (arylene sulfide) resin is usually ASTM D1238 (316 ° C / 5kg, 5 kg
Melt flow rate of about 20 to about 500 g / 10 min, when measured according to (Modified to use preheating for minutes). Poly (arylene sulfide) produced by the method of the present invention
The composition exhibits a melt flow rate within the desired range.

The following example is included to illustrate the invention,
It is not meant to limit the scope of the invention.

Example In the following example, the melt flow (MF) value is measured by the method of ASTM D-1238, condition 316/50, modified to use preheating for 5 minutes, and the MF value is expressed as g / 10 minutes. .
The melt stability of the polymer is dependent on a 5 minute hold prior to extrusion.
It was assessed by the MF change between MF (MF5) and the 30 minute hold modification MF (MF30). This melt stability was calculated according to the formula: [(MF30-MF5) / MF5] x 100 and expressed as% increase. Oxidative stability of PPS polymer sample is 260
Change in polymer MF after heating about 10 g of polymer in a small aluminum pan for 60 minutes in a forced draft oven at ℃ (MF
-Ox). The change in melt viscosity after air oxidation is calculated by [(MF-MF-ox) / MF] x 100, and the change%
It was expressed as Small changes indicate good oxidative stability.

Solvent extraction is carried out with a Soxhlet extractor (So
xhlet extractor) for about 7 hours. The methylene chloride or acetone extract was evaporated and vacuum dried overnight in a medium temperature (80 ° C.) vacuum oven. The extraction amount from the original sample is expressed as an extraction weight% based on the weight of the original sample.

Polymer ash level was measured by burning a weighed portion of the polymer in a platinum dish.
Residual carbonaceous matter is 538 ℃ in the Muffle furnace.
Removed by heating to (1000 ° F). The weight of the residue (ash) is expressed as% of the original weight of the polymer.

Elemental analysis was performed using neutron activation for chlorine and inductively covpled plasma for other elements. The physical properties of the fibers were measured using an Instron tensile tester.

Example 1 This example is a reduced caustic polymerization recipit for melt and oxidative stability.
Demonstrate the importance of e). Polymer 1 was a control polymer made at high caustic levels and Polymer 2 was made by the low caustic process.

50.52 wt% NaOH solution 73.0 lb. (33.1 kg) with NaSH 59.17
Wt% and Na ₂ S 0.12 wt% solution 87.3 lb. (39.6 kg)
An aqueous solution of sodium sulfide was prepared by mixing with. This corresponds to a NaOH / NaSH molar ratio of 1.003. This solution was added to the reactor along with solid sodium acetate 23.5 lb. (10.6 kg) and NMP 35.7 gallons (135), then the reactor was suffocated. The mixture was dehydrated by heating to 332 ° F (167 ° C) and raising the temperature to 445 ° F (229 ° C) over 81 minutes.

DCB 134.8 lb. (61.14 kg) was added and the reactor mixture was 451
Heat to ° F (233 ° C) and hold for 2 hours, final pressure 74psig
Reached. When the reactor temperature was raised to 510 ° F (266 ° C) and held for 3 hours, a pressure of 162 psig was reached.

Cool the contents of the reactor to about 275 ° F (135 ° C) and stir the contents at a rotor speed of about 400 rpm while stirring with liquid water.
Gallon (37.8) was added to the reactor. 225 ° F (107 ° C)
Cooling was continued until the temperature of was reached. The total cooling time from 510 ° F (226 ° C) to 225 ° F (107 ° C) was about 117 minutes.

Then pass the slurry through and liquor the solution at 159 ° F (70 ° C) NaOH.
1 by 80 gallons (302.4) of 160g deionized water
It was washed twice with 80 gallons of water containing 316 g of calcium acetate at 160 ° F (71 ° C). 200-300 filter cake
Polymer 1 was obtained by drying at ℃ (93-149 ℃) and atmospheric pressure for about 3 hours.

Polymer 2 was prepared in the same manner as Polymer 1 above, but in this case 68.8 lb. (31.1 kg) NaOH solution was used to obtain a NaOH / NaSH molar ratio of 0.946. Sodium acetate
A 28.0 lb, (12.7 kg) charge was added to the mixture prior to dehydration, from an initial 330 ° F (166 ° C) to a final 440 ° F (299 ° F).
Dehydration time to (° C) was 87 minutes. Water cooling process is 510
It took 126 minutes to reach 225 ° F (107 ° C) from 225 ° F (266 ° C). Polymer 2 was recovered and washed as above except a calcium acetate wash temperature of 180 ° F (82 ° C) was used.

Melt flow rate (MF) was used to measure the melt stability of polymers 1 and 2.
It was carried out on a measuring device and the results are shown in Table I.

Polymer 2 produced by the low caustic method had less change in MF after holding for 30 minutes than polymer 1 produced by the high caustic method.

The oxidative stability of polymers 1 and 2 was evaluated at 260 ° C (500 °
It was carried out by measuring the change in MF of the sample by heating them for 1 hour in the forced draft oven of F). The results are shown in Table II.

Polymer 2 produced by the low caustic method showed a smaller MF change during the oxidation process than polymer 1 produced by the high caustic method.

Example 2 This example illustrates the value of using NMP as an extractant to reduce the levels of extractables in PPS products.

The polymers in this example and some of the following examples were prepared in the same manner as described in Example 1, except for the noted changes. All NaOH solutions were about 48% by weight, NaSH solutions were either 25% or 47% by weight, and sodium acetate solutions were about 42% by weight. The cooling rate from the end of the polymerization cycle was about 1 ° C./minute. All washes were performed with approximately 770 liquids. The filtration was carried out with a shaker screen using a 200 mesh screen. Polymer drying was performed with a suffocation cover in the dryer.

The amount of NaOH, NaSH and DCB used for each polymer is
The results are shown in Table III.

In each polymerization run, 0.37 kg mol of sodium acetate (3
0.34 kg) and NMP 3.33 kg mol (289.7 kg) were used. In Run 3, the polymerization temperature was raised from 220 ° C to 270 ° C for 160 minutes and maintained at 270 ° C for 110 minutes. Polymer 5 was added to the mixture before dehydration and before polymerization in two batches of 80 g each, sodium dithionite (Na ₂ S ₂ O ₄ ) 160 g, NaOH 0.25 g, H
Prepared using 385 g of 2O. Polymer 4, 5 and 6
Manufactured with a constant rise from 235 ° C to 270 ° C over 170 minutes.

18 kg of liquid water at the end of polymerization for all 4 polymerizations
Added at 270 ° C. The cooled mixture of runs 3 and 5 was added to water, filtered and washed. In Runs 4 and 6, the cooled mixture was added to NMP330 at 70 ° C, passed and washed.
The wash procedure included one wash with water at ambient temperature, two washes with water at 70 ° C, one wash with water containing 480 g of calcium acetate at 70 ° C and a final rinse with water at 70 ° C.

Polymers 3 and 4 were extracted with methylene chloride to determine the amount of extractable material. The results are shown in Table IV.

The results show that NMP extracted polymer 4 contains lower levels of extractable material than water cooled recovered polymer 3. Several inorganic elements contained in polymers 4 and 5 were quantified for comparison.

As shown in Table V, NMP extracted polymer 4 contained lesser amounts of sodium and chloride than water cooled recovered polymer 5.

Polymers 3 and 6 were combined with another batch of PPS prepared in the same manner, equipped with a 26 inch mercury vacuum vacuum vent and a screen pack containing 325 mesh screen.
Pelletized with a mm twin screw extruder. The pellets were dried in a rotary vacuum oven at about 125 ° C. for about 5 hours and were then covered with a large area Fluid Dynamics (Brunswick, Deland, Florida) Dynalloy X13L filter, metering pump and 0.
It was spun into continuous monofilament at 290 ° C. in a 2 inch diameter extruder equipped with 4 spinnerets containing 100 48 mm diameter holes. Unstretched fibers are steamed at 100 ° C.
chest) stretched about 3.4 times, and about 150 on hot roll
Annealed (thermoset) at ° C. The fiber spinning results and physical properties are shown in Table VI.

Water-cooled recovery polymer 3 was wiped twice on the spinneret surface to remove oil accumulated during the spinning time of 2.8 hours.
e) needed. However, the NMP produced according to the present invention
Extracted Polymer 6 required only one wipe of the spinneret surface during the 3.2 hour spinning time. The fiber physical properties of the two polymers were the same. Therefore,
The NMP-extracted polymers of the present invention have only low levels of volatiles that can adhere to the spinneret surface during fiber spinning.

Example 3 This example demonstrates that the use of calcium salt washes of PPS polymers improves the thermal stability of fibers made from the polymers. Polymers 7 and 8 were prepared using a dilute aqueous acetic acid wash to remove inorganic ions. Polymer 9 was prepared using calcium acetate to introduce calcium ions.

Polymerizations of Polymers 7-9 were carried out in the same manner as described in Example 2, except for the modifications described here. NaOH, NaS
The amounts of H and DCB used are shown in Table VII.

In all cases 0.37 kg mol sodium acetate (30.34 k
g) and NMP 33.3 kg mol (329.7 kg) were used. All polymerizations were carried out at 235 ° C for 5 hours and 270 ° C for 3 hours. At the end of the polymerization step at 270 ° C., 18 kg of liquid water was added to polymers 7 and 9, and to polymer 8 9 kg of liquid water was added. The cooled reaction mixture from Polymerizations 7 and 8 was added to NMP300.
In addition, pass once with water at ambient temperature and 2 with water at 70 ° C.
It was washed once with water at 177 ° C, then washed with acetic acid solution at pH 5.0 and 70 ° C to remove a part of inorganic ions, and further washed once with water at 70 ° C. The cooled polymerization mixture from Polymerization 9 was diluted with water, passed, once with ambient temperature water, four times with 70 ° C. water, once with an aqueous solution containing 480 g of calcium acetate, and 70 times.
It was washed once with water at ℃. All polymers were dried as described in Example 2.

Break these polymers into a breaker plate (breaker pl
pelletized in a 1.25 inch diameter extruder equipped with a screen pack containing a 325 mesh screen in ate) using a melt temperature of 305 ° -317 ° C. The pellets were dried in a vacuum oven at 125 ° C. overnight and spun into fibers in a 1 inch diameter spinning machine equipped with a metering pump and a 34 hole spinneret with holes 0.048 inches long and 0.012 inches in diameter. Result is VIII
It is shown in the table.

Stretch the fiber sample on a 100 ° C hot plate and
After heat curing the fiber for 30 minutes on a metal tube at 00 ℃,
The fiber physical properties shown in the table were the same. For the evaluation of fiber thermal stability, the fibers were aged on a metal tube in a forced air oven at 200 ° C. As shown in Table VIII, the calcium-treated polymer 9 had high thermal stability. That is, this polymer 9 is slower than the acid cleaning polymers 7 and 8 and
Reached 2 (1/2 x strength x elongation).

Example 4 This example illustrates large scale production of PPS polymers and fibers using the present invention. Polymer 10 was a comparative polymer made by conventional solvent flashing and polymer 11 was made by the NMP extraction of the present invention.

In a typical batch production of Polymer 10, 50.26 wt% NaOH solution 1835 lb. (832.4 kg) was added to NaSH 59.86 wt% and Na
An aqueous sodium sulfide solution was prepared by mixing with 2171 lb. (984.8 kg) of a solution containing 0.100 wt% OH. Na
The OH / NaSH molar ratio was 0.997. This solution is NMP 46
52 lb. (2110 kg) and 30 wt% NaoAc 200 gallons were added to the reactor. The mixture was dehydrated by first heating to 237 ° F (134 ° C) and then raising the temperature to a final temperature of 405 ° F (207 ° C) within 65 minutes.

The dehydrated mixture was then transferred to the polymerization reactor and the DCB 3425
lb. (1554 kg) and NMP 2449 lb. (1111 kg) (to flush the dehydration vessel) were added to the polymerization reactor. The entire reaction mixture was run from 407 ° F (208 ° C), 9 psig initial to 475 ° F (24 ° C)
6 ° C), heated to 71 psig for 145 minutes. Next, set the reaction conditions to 50.
0 ° F (260 ° C), increased to 175psig, from the start of temperature rise
After 65 minutes, 350 ml of 1,2,4-trichlorobenzene (TCB) was added. After charging TCB, the reaction pressure was increased to 23 with CO ₂ .
The reaction was increased to 5 psig and continued at 510 ° F (266 ° C) for a further 30 minutes to a final condition of 219 psig.

The polymerization mixture was concentrated by partial solvent flash at about 510 ° F (266 ° C), pressure was 218 psig to 60 p in 49 minutes.
dropped to sig. Finally, concentrate the slurry to about 540 ° F.
Flush for 58 minutes in a blender heated to (282 ° C) and heated to 460 ° F (238 ° C). The dry PPS containing salt was washed with water at ambient temperature and passed over a belt filter. Slurry filter cake in water at 375 ° F
(190 ° C), with steam condensate at 240 psig,
If necessary, replenish with plant water for cleaning, and wash at 190 ° F (88
℃) and passed through a belt filter. It was then dried at about 290 ° F (143 ° C) at atmospheric pressure with a residence time of about 30 minutes.

This batch of solvent-flushed PPS was combined with several similar batches to make polymer 10.

Polymer 11 was prepared by the low caustic method, NMP extraction and calcium acetate wash. Several batches of polymer were combined to produce a lot containing approximately 2400 kg. A typical polymerization method is 1.120 kg mol of NaSH, 1.092 kg mol of NaOH, DC
B 1.110kgmol, sodium acetate 0.37kgmol, NMP 3.33k
g mol was used. The NaOH / NaSH molar ratio was 0.975. The same procedure as described for polymers 4 and 6 of Example 2 was used but in this case one additional 70 ° C. wash was performed before the calcium acetate wash. This polymer batch is 168g / 1
It had a melt flow rate of 0 minutes.

Polymers 10 and 11 open vent, screen changer including 325 mesh screen and water ring pelletize
pelletized by a 4.5 inch diameter single screw extruder equipped with r).

Pellets of polymers 10 and 11 were compared and the results are shown in Table IX.

Table IX shows that the inventive polymer 11 is lighter in color and has a lower ash, iron, nickel, sodium and chlorine content than the control polymer 10.

Polymer 11 of the present invention was spun into fibers using pellets dried in a commercial forced draft hopper dryer at about 100 ° C. Spinning was carried out using a 2.5 inch diameter extruder equipped with a wide range Fluid Dynamics (Brunswick, Deland, FL) Dynaloy X13L filter, metering pump and 12 100 hole spinnerets with 0.48 mm diameter holes. There was a 325 mesh screen in the spin pack. The spinning performance was very good, the pressure rise of the filter and spin pack was very slow, and there was almost no adhesion to the die surface. PPS fiber was collected on the tube at 900 m / m. Four fiber packages were placed in a steam chest with 4-8 psig steam and stretched. The stretching conditions are
3.27 x draw ratio with ambient temperature supply roll at 100 m / m and 100 ° C draw roll temperature. 1212 drawn fiber
Denier, tenacity 3.0 gpd and stretch 22
%.

A control resin similar to polymer 10 was pelletized and stretched as described above. The pressure on the field filter and spin pack screen rose faster than with Polymer 11. Die face attachment was more frequent than with Polymer 11 and the die face was wiped every 8 hours. Attempts to draw fibers in the above drawing apparatus have been unsuccessful.

Example 5 This example illustrates PPS polymerization using two NMP extractions. Polymers 12 and 13 were prepared in the same manner as described for polymer 11 in Example 4, except for the modifications described herein. Both polymers are 1.120 kg mol NaSH, 1.081 kg mol NaOH, DCB
1.10 kg mol, sodium acetate 0.37 kg mol, and NMP3.3
Prepared using 3 kg mol. The NaOH / NaSH molar ratio was 0.965. The polymerization was carried out for 170 minutes using a continuous temperature increase from 235 ° C to 270 ° C. An 18 kg charge of water was added to the reaction mixture near the end of the polymerization process at 270 ° C. The reaction mixture from polymer 12 was added to NMP 330. For polymer 13, NMP 100 was added to the 200 ° C. polymerization mixture and the resulting mixture was added to NMP 220. Both solutions were passed and washed as described for polymer 11 in Example 4.

 Table X contains the evaluation results for both polymers.

Both polymers were similar in viscosity, ash, sodium and calcium levels. Polymer 13 is polymer 12
It has a slightly lower level of acetone extractables.
Both NMP extraction methods yielded PPS polymers with low levels of solvent extractables.

Although the present invention has been described in detail for purposes of illustration, it is not intended to limit the invention thereto, and this description is meant to include all modifications that are reasonable within the spirit and scope of the invention.

Claims (12)

(57) [Claims] 1. A method for producing a poly (arylene sulfide) composition useful for producing fibers and monofilaments, comprising the steps of: (a) a sulfur source, a polar organic compound, a base and an alkali metal carboxylate under dehydration conditions. To form a dehydration mixture such that the molar ratio of the base to the sulfur source before dehydration does not exceed about 0.98: 1, and the dehydration mixture is then subjected to at least one dihalogen under suitable conditions. Forming a substantially liquid mixture of a poly (arylene sulfide) resin, a polar organic compound and water by contacting with a fluorinated aromatic compound; (b) annealing the mixture and then at least one An effective amount of extractant is added to the mixture to form a slurry of solid poly (arylene sulfide) particles and a liquid containing non-polymeric material and low molecular weight material. A step of forming; (c) a step of bringing the poly (arylene sulfide) particles into contact with an aqueous solution containing calcium ions; and (d) a step of recovering the poly (arylene sulfide) composition. 2. The method according to claim 1, further comprising the step of adding a separating agent before the slow cooling in step (b). 3. The method of claim 2 wherein said separating agent is water and said separating agent is used in an amount within the range of about 0.05 to 2 moles per mole of said polar organic compound. 4. The extractant and the separating agent are used together, and these are about
N-methyl-2 at a molar ratio within the range of 1: 1 to 10: 1
A process according to claim 2 which is a mixture of pyrrolidone and water. 5. The method according to claim 1, wherein the polar organic compound and the extractant are N-methyl-2-pyrrolidone. 6. A process according to claim 5, wherein the molar ratio of the added extractant to the polar organic compound used is in the range of 05: 1 to 2: 1. 7. The method according to claim 1, wherein in step (c), the aqueous solution is an aqueous solution of calcium acetate. 8. The method according to claim 1, wherein the sulfur source is sodium hydrogen sulfide. 9. The method according to claim 1, wherein the base is sodium hydroxide. 10. The method according to claim 1, wherein the alkali metal carboxylate is sodium acetate. 11. The method according to claim 1, wherein the dihalogenated aromatic compound is dichlorobenzene. 12. The polar organic compound is N-methyl-2-
The method according to any one of claims 1 to 11, which is pyrrolidone.